1. Field of the Invention
The present invention generally relates to a substrate and method of cleaning a semiconductor manufacturing apparatus using the same. More particularly, the present invention generally relates to a substrate having catalyst layer thereon and method of cleaning a reaction chamber using the same.
A claim of priority is made to Korean Patent Application No. 2004-6794, filed Feb. 2, 2004, the contents of which are incorporated by reference.
2. Discussion of Related Art
FIG. 1 is a schematic view of a conventional plasma enhanced chemical vapor deposition (PECVD) apparatus 10. PECVD apparatus 10 includes a reaction chamber 11, a susceptor 12 fixed on the bottom portion of reaction chamber 11, an upper electrode 13 opposite susceptor 12 and connected to an RF power (not shown) through a connector 14, a gas inlet 15 provided in a wall of reaction chamber 11, and at least one vacuum pump system 16 provided outside of reaction chamber 11. Upper electrode 13 has a shower head shape, and a plurality of gas distribution holes 13a formed therein.
To form a layer on a substrate, reaction chamber 11 is set to a vacuum condition. The substrate is transferred into reaction chamber 11 and then placed on susceptor 12. Next, a deposition source gas and an inert gas are introduced into reaction chamber 11 through gas inlet 15. The gases introduced into reaction chamber 11 are mixed and then distributed toward the substrate through gas distribution holes 13a. As a result, the mixed gases are introduced into a reaction space between upper electrode 13 and susceptor 12. RF power is applied to upper electrode 13 to generate plasma gas within the reaction space. As ions of the deposition source gases reach the substrate, a layer is formed on the substrate.
However, it is inevitable that contamination layers are formed. Specifically, the contamination layers are formed on inner walls of reaction chamber 11, on upper electrode 13, and on susceptor 12. As the process reactions are repeated, the contamination layer increases in thickness. Particles from the contamination layers peel off and may fall on a substrate during a deposition process, thereby resulting in various device failures.
Accordingly, a cleaning process is required to remove the contamination layers. A cleaning process is carried out by introducing a cleaning gas into reaction chamber 11 to create a reaction between the contamination layer and the cleaning gas with the aid plasma and heat, thereby changing the solid contamination layer into a gas phase. Thereafter, the contamination gas may be exhausted from reaction chamber 11.
In particular, the thickest layer of contamination is formed on the surface of upper electrode 13 facing susceptor 12. Accordingly, when a cleaning process is carried out of sufficient intensity to remove the thickest contamination layer from upper electrode 13, other surface in reaction chamber 11 may be damaged. Further, if the cleaning process is performed while suscepetor 12 is exposed; the surface of susceptor 12 may be damaged as the cleaning process is repeated many times, even though the bias power applied to susceptor 12 is zero.